Combined expansion and counterboring bit



W. F. WALL.

COMBINE-D EXPANSION AND coumanaomm; BIT.

APPLICATION FILED JAN. 25. 192]- Patented Aug. 8, 1922 STATES FATEWILLIE IE. WALL, 01' WATBDNVILLEQCALIFORNIA.

commune nxransron' AND oovu'rnanoame m.

naaaeoo.

Specification of Letters Patent.

Patented Aug. 8, H922.

Application filed January 25, 1921. Serial No. 439,790.

Cruz and State of California, P. O. Box.

153, have invented a new and useful Improvement in a Combined Expansionand Counterboring Bit, of which the following is a specification.

My invention relates to improvements in combined expansion andcounterboring bits of the type disclosed in my copending Npplicationfiled October 29th, 1920; Serial 0. 420,456, reference to which ishereby made.

The present invention consists of providing a longitudinally disposedgroove upon the head of the tool within which the cutting bits areadjustably mounted, the object being to prov1de a greater range ofadjustment of said bit longitudinally upon the tool.

I accomplish these and other objects by means of the improved formdisclosed in the drawings forming a part of the present specificationwherein like characters of reference are used to designate similar partsthroughout the said specification and drawings, and in which Fig. 1 is abroken front elevation of my invention, one cutter blade being inposition to adapt the bit for boring holes;

Fig. 2 is a similar view, disclosing another cutter blade in positionfor counterboring a hole;

F'i 3 is a broken side elevation of Fig.' 1 wit the lower cutter bladeremoved; and

Fig. 1 is an enlarged transverse sectional view taken on line 44 of Fig.3 in the direction indicated.

Fig. 5 is a rear view of one of the cutter blades;

Referring to the drawings the numeral 10 is used to designate the shankof the bit and 11 the head comprising an upper semi-cylindrical portion12 and a lower semi-conical port-ion 13. The flat sides of the portions12 and 13 lie in the same plane as the axis of the bit or the shank 10and are provided with lateral and longitudinal serrations 16 throughoutthe entire surface of said fiat sides, the purpose of which willhereinafter be more fully set forth.

A lead screw 14 and a cutting flange 15 are provided on the lower orapex end of the semi-conical portion 13 to facilitate entrance andboring of the tool into the materialto be operated upon.

In place of the clamp 19 disclosed in my copending applicationhereinbefore referred to the head 11 is provided with a co-axial dovetaileol groove 17 having an enlarged opening 19 at the upper end thereofto facilitate the introduction of a head 20 slidably mounted within saidgroove 17 and arranged for longitudinal movement only within said groove17 to provide axial adjustment for either one of a pair oflongitudinally slotted cutter blades 21.

The cutter blade 21 is providedwith a substantially horizontal cuttingportion 25, as in my copending application above referred to, which willcut away the wood in a substantially horizontal plane within the limitsof the scoring lip on the cutter as shown in the drawings. Fig. 1 showsthe shorter cutting lip in operative position operating as an expansionbit, while Fig. 2 shows the upper longer cutter blade in operativeposition as a counterbore. As the tool is rotated the horizontal cuttingedge 25 cuts away the wood immediately thereunder as shown. As acounterbore, the tapered portion of the head is positioned in apreviously bored hole, and the cutter adjusted longitudinally tointersect the tapered edge of the head at the point of engagementwiththe hole, and adjusted laterally to give the desired diameter ofcounterbore. The taper-v ed portion may thus be fitted to any holej v20will be clamped tightly against the angular sides of the groove 17 andthe adjacent face of the cutter blade 21, which is also serratedlongitudinally and laterally, as at 25, as disclosed in Fig. 5 of thedrawings, is tightly clamped against the serrated surface of the head11, thereby preventing movement of said cutter blade 21 relatively terblade; an

ree which is only limited by the distance etween the longitudinal andlateral serrations 16.

As these serrations 16 are longitudinally and laterally disposed as wellas the serrations on the rear sides of the cutter blades 21 it isobvious that the said blades 21 are effectively held a ainst movement bythe engagement of sai serrations when the screw 22 is tightened.

Reduction to practice has disclosed that the clamps 19 disclosed in mycopending application referred to must be made conslderably lar er thandisclosed in said application. T e provision of the slot 17 thereforehas eliminated the use of cumbersome and expensive parts whichmaterially limited the range of adjustment.

It is obvious from the foregoing that I have provided an improved andsimplified form of construction whereby a greater range of adjustabilitymay be obtained with fewer arts.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is 1. A combined expansion and counterboringbit comprisin a semi-conical head provided with a lea screw and acutting flange; and having a longitudinal groove disposed alon the axisof the head; a cutmeans operativel connected to the blade and slidablyengaging the slot whereby said cutter blade may be adjustedlongitudinally and radially.

2. A combined expansion and counterboring bit comprising a head having alower semi-conical and an upper semi-cylindrical portion and provided atthe lower end of the semi-conical portion with a lead screw and acutting flange, the flat sides of said semi-cylindrical and semi-conicalportions lying in the plane of the axis of said bit andhaving a groovelongitudinall disposed {thereonalong the axis 0 the Bea a cutter blade';and means slidabl mounted within 'the groove for adjustabdy connectingthe cutter blade to the flat si of sai head to permit longitudinal andradia adjustment.

35A combined expansion and counterboring bit comprisin a semi-conicalhead provided with a lea screw and a cutting flange and having ,a grooveformed lon tudlnally along the axis upon the flat side of said head; anut mounted slidably for longitudinal movement only within said groove;and a cutter blade detachably and slidably connected to said nut toprovide axial and radial adjustment of said blade. 4. A combinedexpansion and counterboring bit comprising a semi-conical head having alead screw and a cuttin flange and a dove-tailed groove arrange withinsaid .head and along the axis of the bit, a nut slidably mounted forlongitudinal movement only within said slot; a longitudinally slottecutter blade; and means for engaging the slot in the cutter blade andthe nut for longitudinal and radial adjustment of said blade.

5. A combined expansion and counterboring bit comprising a semi-conicalhead having a lead screw' and a cutting flange and likewise providedwith a groove longitudinally. disposed along the axis, said groovehaving-an enlarged end for the introduction of a nut; a nut slidablymounted within the slot; a longitudinally slotted cutter blade radiallypositioned on said head; and means for slidably engaging the cutterblade slot and detachably connectin said blade with said nut forlonitudina and radial adjustment of said bla e.

In witness whereof I hereunto set my signature.

WILLIE F. WALL.

